Printing mechanism

Abstract

A printing mechanism 1 including a mandrel 2 , and a tubular sleeve 3 ; wherein the mandrel comprises a main body and sleeve support members 6 , a plurality of the sleeve-support members being arranged on the main body at intervals in the axial direction; and wherein the sleeve-support member has a plurality of arm portions 7 extending radially so as to support the sleeve from an inside thereof, and moving mechanisms 8 for moving tip vicinities of the arm portions inward/outward in the radial direction; and wherein the sleeve-support member has an interlock mechanism 9 for synchronously driving each moving mechanism of the sleeve support members, the tip vicinities of the arm portions being engaged with the inner surface of the sleeve or released from the engaged inner surface of the sleeve by the synchronous motion of the tip vicinities of all arm portions inward/outward with the interlock mechanism.

The invention claimed is: 
     
       1. A printing mechanism including a mandrel, and a tubular sleeve to be mounted on the mandrel, having an outer peripheral surface to which printing plates are attached;
 wherein the mandrel comprises a main body and sleeve support members arranged on an outer periphery of the main body, 
 a plurality of the sleeve-support members being arranged on the main body at intervals in the axial direction; 
 and wherein each respective sleeve-support member has a plurality of arm portions extending radially so as to support the sleeve from an inside thereof, and respective moving mechanisms for moving tip vicinities of the arm portions inward and outward in the radial direction; 
 and wherein each respective sleeve-support member further has an interlock mechanism for synchronously driving each moving mechanism of the sleeve support members, the tip vicinities of the arm portions being engaged with the inner surface of the sleeve or released from the engaged inner surface of the sleeve by the synchronous motion of the tip vicinities of all arm portions inward and outward with the interlock mechanism. 
 
     
     
       2. The printing mechanism according to  claim 1 ,
 further comprising a connecting member extending along the main body in order to connect mutually the plurality of the sleeve support members, 
 wherein the connecting member is connected with one of the tip vicinities of the arm portions among the plurality of arm portions of each of the sleeve support member. 
 
     
     
       3. The printing mechanism according to  claim 2 ,
 wherein, each sleeve support member is equipped with a base portion provided on the main body, 
 the vicinity of the base end of the arm portion being pivotably supported swingably to the base portion, and the tip vicinity thereof being pivotably supported swingably to the said connecting member, and wherein 
 the sleeve support member is made to be a plurality of pairs in which each pair consists of adjoining sleeve support members, and wherein the interlock mechanism is that which makes the both base portions of each pair of sleeve support member approach or separate, the tip vicinities of the arm portions being moved inward and outward radially by the approach or the separation of those base portions. 
 
     
     
       4. The printing mechanism according to  claim 1 ,
 wherein the moving mechanism is a hydraulic cylinder to extend and retract the arm portions. 
 
     
     
       5. The printing mechanism according to  claim 2 ,
 wherein the moving mechanism is a hydraulic cylinder to extend and retract the arm portions.